cone

cone downloads the stars around a position from a VizieR catalogue.

It asks a VizieR server for all stars within a radius of a position and saves them as a FITS table or a VOTable, sorted by magnitude. This is how you get the reference catalogue that astrometry, phcal and artificial need. Pass the catalogue’s column names to those routines (for UCAC4: RAJ2000, DEJ2000, pmRA, pmDE, Vmag).

cone needs network access. To get the coordinates of an object by its name, use sesame; to convert a VOTable or draw a chart, use votable; to match two catalogues, use cross.

Usage

munipack cone [options] [--] RA DEC
munipack cone --list-catalogues | --list-servers

RA and Dec are in decimal degrees. Put -- before them when the declination is negative, so that it is not read as an option.

Options

Catalogue and server

Option	Default	Description
-c, --cat alias	UCAC4	Predefined catalogue; a prefix is enough (-c Gaia).
--id ID	—	Any VizieR catalogue by its identifier, e.g. V/154.
--server alias	CDS	VizieR mirror (see --list-servers).
--url URL	—	Full query URL instead of catalogue and server.
--vocat file	installed VOcat_conf.xml	Catalogue definitions (aliases, IDs, column names, mirrors).
--list-catalogues	—	List the predefined catalogues and their columns.
--list-servers	—	List the VizieR mirrors.

Selection

Option	Default	Description
-r, --radius deg	0.1 (6 arcmin)	Search radius.
--magmin mag	—	Bright limit: keep only fainter stars.
--magmax mag	—	Faint limit: keep only brighter stars.
-s, --sort column	catalogue magnitude	Sort by this column; the magnitude limits apply to it.
--par key=value	—	Extra VizieR constraint, e.g. '-out.max=500'.
--Johnson-patch	off	UCAC4 only: convert Gunn r, i to Johnson R, I.

Output

Option	Default	Description
-o, --output file	cone.fits	Output file; a suffix other than .fits gives a VOTable.
--type fits|votable	by suffix	Output format.
--verbose	off	Print the query and the server’s answer.
-h, --help	—	Show the help.

Output

The FITS output is a single binary table with every catalogue column plus _r, the distance from the centre. The epoch of the positions is stored in the JEPOCH header keyword when the catalogue provides it. A VOTable output can be converted later with votable.

Examples

UCAC4 stars within 0.3° of M67:

munipack cone -r 0.3 -o m67.fits -- 132.85 11.81

Gaia DR3 stars brighter than G = 17 at a southern position:

munipack cone -c Gaia --magmax 17 -r 0.2 -o field.fits -- 245.9 -26.5

Any VizieR catalogue by its ID. Munipack does not know its magnitude column, so name it with --sort for the limit to work:

munipack cone --id V/154 -s umag --magmax 20 -r 0.2 -o sdss.fits -- 180.0 0.0

Notes

• The aliases of -c and --server are case-sensitive. If both -c and --id are given, -c wins.

• Only the last --par is used; join several constraints with &.

• To give your own catalogue an alias, copy VOcat_conf.xml, add a row to its CATALOGUE table and pass the copy with --vocat.

• When nothing matches, cone says so and writes no file.